From owner-freebsd-hackers@FreeBSD.ORG Thu Jul 31 20:19:54 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 04CCA37B401 for ; Thu, 31 Jul 2003 20:19:54 -0700 (PDT) Received: from smtp-out2.blueyonder.co.uk (smtp-out2.blueyonder.co.uk [195.188.213.5]) by mx1.FreeBSD.org (Postfix) with ESMTP id E7B2743FE0 for ; Thu, 31 Jul 2003 20:19:52 -0700 (PDT) (envelope-from bruce@cran.org.uk) Received: from buffy.brucec.backnet ([82.41.200.71]) by smtp-out2.blueyonder.co.uk with Microsoft SMTPSVC(5.0.2195.5600); Fri, 1 Aug 2003 04:19:51 +0100 Received: from buffy.brucec.backnet (localhost [127.0.0.1]) by buffy.brucec.backnet (8.12.9/8.12.9) with ESMTP id h713Jp83034556; Fri, 1 Aug 2003 04:19:51 +0100 (BST) (envelope-from bruce@buffy.brucec.backnet) Received: (from bruce@localhost) by buffy.brucec.backnet (8.12.9/8.12.9/Submit) id h713JpIc034555; Fri, 1 Aug 2003 04:19:51 +0100 (BST) Date: Fri, 1 Aug 2003 04:19:51 +0100 From: Bruce Cran To: soralx@cydem.org.ua Message-ID: <20030801031951.GA33188@buffy.brucec.backnet> References: <200307311455.h6VEtx5i088476@spider.deepcore.dk> <20030731105545.B85113@alpha.yumyumyum.org> <200307311833.28209.soralx@cydem.org.ua> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200307311833.28209.soralx@cydem.org.ua> User-Agent: Mutt/1.4.1i X-OriginalArrivalTime: 01 Aug 2003 03:19:51.0903 (UTC) FILETIME=[C5796EF0:01C357DB] cc: freebsd-hackers@freebsd.org Subject: Re: Ultra ATA card doesn't seem to provide Ultra speeds. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Aug 2003 03:19:54 -0000 On Thu, Jul 31, 2003 at 06:33:28PM -0600, soralx@cydem.org.ua wrote: > > > > Maybe not, but they do give a transferspeed from medium range and that > > > is what can be expected. > > > > Hmm, I guess not everyone does that. We have some seagates here at work we > > were wondering about because they seemed too slow, and we couldn't find > > anything aside from what we already knew... the tranfer speed of the > > SCSI interface, which is basically from drive cache to controller. That is > > unless the manufacturers hide the info somewhere so you really have to > > dig, which wouldnt' surprise me. > > Example took me less than 64 seconds to find (for Seagate Barracuda IV): > http://www.seagate.com/cda/products/discsales/personal/family/0,1085,559,00.html > Look for 'Avg. Sustained Transfer Rate'. AFAIK, every manufacturer I know > gives the sustained transfer rate specs (which are sometime a bit too high than > in reality). If the specs are not specified, it'd be very suspicious, and I > would think 128 time before buying such drives. > The transfer rates are usually given for the outside of the disk I think. Speeds usually drop about 15-20MB/s between the outside and inside. If you've got FreeBSD 5.1, you can use the 'diskinfo -t ' command to measure the performance of the hard drive. It should be a little more accurate than using dd, because I'm guessing the reads/writes don't go through the vfs layer. -- Bruce Cran